pjsip-pjproject/pjlib/include/pj/list.h

290 lines
8.5 KiB
C

/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PJ_LIST_H__
#define __PJ_LIST_H__
/**
* @file list.h
* @brief Linked List data structure.
*/
#include <pj/types.h>
PJ_BEGIN_DECL
/*
* @defgroup PJ_DS Data Structure.
*/
/**
* @defgroup PJ_LIST Linked List
* @ingroup PJ_DS
* @{
*
* List in PJLIB is implemented as doubly-linked list, and it won't require
* dynamic memory allocation (just as all PJLIB data structures). The list here
* should be viewed more like a low level C list instead of high level C++ list
* (which normally are easier to use but require dynamic memory allocations),
* therefore all caveats with C list apply here too (such as you can NOT put
* a node in more than one lists).
*
* \section pj_list_example_sec Examples
*
* See below for examples on how to manipulate linked list:
* - List sample: \src{pjlib/src/pjlib-samples/list.c}
* - List test: \src{pjlib/src/pjlib-test/list.c}
*/
/**
* Use this macro in the start of the structure declaration to declare that
* the structure can be used in the linked list operation. This macro simply
* declares additional member @a prev and @a next to the structure.
* @hideinitializer
*/
#define PJ_DECL_LIST_MEMBER(type) \
/** List @a prev. */ \
type *prev; \
/** List @a next. */ \
type *next
/**
* This structure describes generic list node and list. The owner of this list
* must initialize the 'value' member to an appropriate value (typically the
* owner itself).
*/
struct pj_list
{
PJ_DECL_LIST_MEMBER(void);
} PJ_ATTR_MAY_ALIAS; /* may_alias avoids warning with gcc-4.4 -Wall -O2 */
/**
* Initialize the list.
* Initially, the list will have no member, and function pj_list_empty() will
* always return nonzero (which indicates TRUE) for the newly initialized
* list.
*
* @param node The list head.
*/
PJ_INLINE(void) pj_list_init(pj_list_type * node)
{
((pj_list*)node)->next = ((pj_list*)node)->prev = node;
}
/**
* Check that the list is empty.
*
* @param node The list head.
*
* @return Non-zero if the list is empty, or zero if it is not empty.
*
*/
PJ_INLINE(int) pj_list_empty(const pj_list_type * node)
{
return ((pj_list*)node)->next == node;
}
/**
* Insert the node to the list before the specified element position.
*
* @param pos The element to which the node will be inserted before.
* @param node The element to be inserted.
*
*/
PJ_IDECL(void) pj_list_insert_before(pj_list_type *pos, pj_list_type *node);
/**
* Insert the node to the back of the list. This is just an alias for
* #pj_list_insert_before().
*
* @param list The list.
* @param node The element to be inserted.
*/
PJ_INLINE(void) pj_list_push_back(pj_list_type *list, pj_list_type *node)
{
pj_list_insert_before(list, node);
}
/**
* Inserts all nodes in \a nodes to the target list.
*
* @param lst The target list.
* @param nodes Nodes list.
*/
PJ_IDECL(void) pj_list_insert_nodes_before(pj_list_type *lst,
pj_list_type *nodes);
/**
* Insert a node to the list after the specified element position.
*
* @param pos The element in the list which will precede the inserted
* element.
* @param node The element to be inserted after the position element.
*
*/
PJ_IDECL(void) pj_list_insert_after(pj_list_type *pos, pj_list_type *node);
/**
* Insert the node to the front of the list. This is just an alias for
* #pj_list_insert_after().
*
* @param list The list.
* @param node The element to be inserted.
*/
PJ_INLINE(void) pj_list_push_front(pj_list_type *list, pj_list_type *node)
{
pj_list_insert_after(list, node);
}
/**
* Insert all nodes in \a nodes to the target list.
*
* @param lst The target list.
* @param nodes Nodes list.
*/
PJ_IDECL(void) pj_list_insert_nodes_after(pj_list_type *lst,
pj_list_type *nodes);
/**
* Insert a list to another list before the specified element position.
*
* @param pos The element to which the node will be inserted before.
* @param lst The list to be inserted.
*/
PJ_IDECL(void) pj_list_insert_list_before(pj_list_type *pos,
pj_list_type *lst);
/**
* Insert a list to another list after the specified element position.
*
* @param pos The element in the list which will precede the inserted
* list.
* @param lst The list to be inserted.
*/
PJ_IDECL(void) pj_list_insert_list_after(pj_list_type *pos,
pj_list_type *lst);
/**
* Remove elements from the source list, and insert them to the destination
* list. The elements of the source list will occupy the
* front elements of the target list. Note that the node pointed by \a list2
* itself is not considered as a node, but rather as the list descriptor, so
* it will not be inserted to the \a list1. The elements to be inserted starts
* at \a list2->next. If \a list2 is to be included in the operation, use
* \a pj_list_insert_nodes_before.
*
* @param list1 The destination list.
* @param list2 The source list.
*
*/
PJ_IDECL(void) pj_list_merge_first(pj_list_type *list1, pj_list_type *list2);
/**
* Remove elements from the second list argument, and insert them to the list
* in the first argument. The elements from the second list will be appended
* to the first list. Note that the node pointed by \a list2
* itself is not considered as a node, but rather as the list descriptor, so
* it will not be inserted to the \a list1. The elements to be inserted starts
* at \a list2->next. If \a list2 is to be included in the operation, use
* \a pj_list_insert_nodes_before.
*
* @param list1 The element in the list which will precede the inserted
* element.
* @param list2 The element in the list to be inserted.
*
*/
PJ_IDECL(void) pj_list_merge_last( pj_list_type *list1, pj_list_type *list2);
/**
* Erase the node from the list it currently belongs.
*
* @param node The element to be erased.
*/
PJ_IDECL(void) pj_list_erase(pj_list_type *node);
/**
* Find node in the list.
*
* @param list The list head.
* @param node The node element to be searched.
*
* @return The node itself if it is found in the list, or NULL if it is not
* found in the list.
*/
PJ_IDECL(pj_list_type*) pj_list_find_node(pj_list_type *list,
pj_list_type *node);
/**
* Search the list for the specified value, using the specified comparison
* function. This function iterates on nodes in the list, started with the
* first node, and call the user supplied comparison function until the
* comparison function returns ZERO.
*
* @param list The list head.
* @param value The user defined value to be passed in the comparison
* function
* @param comp The comparison function, which should return ZERO to
* indicate that the searched value is found.
*
* @return The first node that matched, or NULL if it is not found.
*/
PJ_IDECL(pj_list_type*) pj_list_search(pj_list_type *list, void *value,
int (*comp)(void *value,
const pj_list_type *node)
);
/**
* Traverse the list to get the number of elements in the list.
*
* @param list The list head.
*
* @return Number of elements.
*/
PJ_IDECL(pj_size_t) pj_list_size(const pj_list_type *list);
/**
* @}
*/
#if PJ_FUNCTIONS_ARE_INLINED
# include "list_i.h"
#endif
PJ_END_DECL
#endif /* __PJ_LIST_H__ */